There are only two candidates for tuberculosis vaccines currently in phase III trials, but 59 others elsewhere in the development pipeline
The global health community has been abuzz with news that the new malaria vaccine, which has been in the development phase for over two decades, appears to greatly reduce the risk of malaria in children in Africa. Yet this exciting success story is just one of nearly 90 promising new medicines, vaccines, and diagnostic techniques stuck in the tangled clinical trials process. What is more, if the clinical trials process doesn't improve it could be years before many of those drugs ever get through the complicated testing process to reach the one billion people in the developing world who suffer from neglected diseases like TB and Dengue Fever. How many malaria deaths could have been prevented if only the clinical trials process had been improved sooner?
In many cases delays occur because steps in the approval process need to be done in sequence, rather than in parallel.
The many other drug and vaccine candidates for neglected diseases waiting in the pipeline for late stages of clinical development must face lengthy, inefficient review processes or non-existent regulatory capacity in the poorest, least developed countries before these technologies can reach the millions in need. Take, for example, tuberculosis (TB), a neglected disease that remains one of the largest causes of death and illness worldwide. According to a report by BIO Ventures for Global Health, there are only two vaccines and treatments for the disease in phase III trials, compared to 59 in the remainder of the pipeline. So what does it take to get a new treatment through the pipeline and into the hands of a patient who needs it?
Coordinating large multi-center trials for TB isn't easy (or quick for that matter). A 2008 article in the Lancet cited two examples where trials had been delayed by a year or more due to regulatory hurdles for multi-national clinical trials. One of these examples, a trial studying a four-month treatment regimen, needed to obtain approvals from 18 authorities in six different countries, and was stalled for two years before patient recruitment could commence. The primary drug being evaluated in this study, Rifapetine, was approved by the FDA in 1998, but the best dosage for people living in endemic areas is still under investigation as of July 2011.
Unfortunately, this story isn't unique. In many neglected disease-endemic countries, approval of clinical trials can take as long as six-24 months. For products that require multiple trials in different subject populations, subsequent application approvals may take an additional six-24 months or longer. And if you need to amend a trial protocol? Approval for that could take up to four months in a low-income setting. In contrast, regulatory approval for trials in the United States and the European Union can generally be obtained within 30-60 days, and trial protocol amendments take a few weeks.
Not only do these delays prevent access to effective treatments by a growing number of patients (over nine million individuals are newly infected per year by TB), they can lead to unnecessary costs that eat away at already small budgets to find new cures for neglected diseases. According to a recent report (PDF) by the G-FINDER project, in 2009, the global total spending on TB drug development was just $180 million, with 78 percent of all TB funding coming from public funders and philanthropic organizations.